Trolley for Transporting Materials on Seamed Roofs

ABSTRACT

A system for transporting materials that traverses seams and stepped sections of a standing-seam type roof includes two trolleys, the lower one of which has ridges on its top simulating roof seams and upon which the wheels of the upper trolley can be placed. When a step in the roof is encountered, the upper trolley can be rolled off the lower trolley onto the upper section of the roof.

This application is a division of copending application Ser. No. 10/903,856, filed Aug. 2, 2004.

BACKGROUND OF THE INVENTION

Typical panel roofing consists of successive metallic sheets of paneling laid side-by-side to form a roofing cover. Each roofing panel is formed by a panel producing machine from metal sheet stock, typically fed from a roll of sheet metal. Forming each panel can include molding ribs down the panel length and forming both lengthwise edges of each panel to enable a mating fit between the abutting lengthwise edges of adjacent panels. Clips interleaved between the adjacent panel edges affix the panels to the roof surface.

Some panel roofs are constructed with panels spanning the width of the roof to eliminate perpendicular seams that have compromised weather-tight integrity. However, with the advent of the Butler MR-24® Roof System, and a seaming machine called a Roof Runner®, shown in U.S. Pat. No. 3,120,828, issued Feb. 11, 1964 to S. O. Gronlund, which can seam the panels with water-tight integrity, roofers have been relieved of having to produce and manipulate large, unwieldy panels on-site to provide a weather-impervious roofing cover.

Prior to installation of panel roofing, the panels must be hoisted to roof level for installation. Once on the roof, the panels then must be transported to a desired position on the roof. If the roof is large, roofers may need to transport the individual panels over substantial distances, including stepped up sections, as described below.

Particularly large surfaces ordinarily are not roofed in a generally continuous, or single-level, surface to avoid the deleterious effects of thermal expansion naturally occurring in the individual roofing panels. That is, over large surfaces, individual roofing panels expand or contract, depending on weather and sun conditions, which may weaken inter-panel seams or even create gaps and expose the building and occupants thereof. Stepping roof sections, or elevating one section relative to an adjacent section by several inches, eliminates this exposure potential. However, stepping a roof renders material transport more problem-atic because roofers need to lift the heavy, elongated roofing materials over the step between adjacent sections in a coordinated fashion.

Stackable trolleys are disclosed in U.S. Pat. No. 3,523,694, No. 3,608,921, No. 5,711,540, No. 6,079,720, and No. 6,257,152. However, known stackable trolleys are designed to maintain relative positioning among stacked trolleys, not to allow for movement of superposed trolleys.

What is needed, and not taught or suggested in the art, is a trolley for transporting materials that can traverse seams and stepped sections of a roof.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in detail below with reference to the following figures, throughout which similar reference characters denote corresponding features consistently, wherein:

FIG. 1 is an environmental perspective view of an embodiment of a trolley for transporting materials constructed according to principles of the invention;

FIG. 2 is a bottom front right perspective view of the embodiment of FIG. 1;

FIG. 3 is an is an environmental perspective view of another embodiment of the invention;

FIG. 4 is an environmental perspective view of another embodiment of the invention;

FIG. 5 is an enlarged perspective view of a portion of the embodiment of FIG. 4;

FIG. 6 is an environmental perspective view of another embodiment of the invention;

FIG. 7 is an enlarged environmental front view of a portion of the embodiment of FIG. 6; and

FIG. 8 is an enlarged environmental side view of the portion of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a trolley 100 for transporting materials that traverses seams S of a roof R. The trolley 100 has a bed 105 mounted on aligned frames 110 that house wheels 115. Once the trolley 100 is positioned on seams S, roofing materials (not shown) are hoisted onto the trolley 100 for transportation to where the materials are needed.

As viewed along direction A, the bed 105 defines a box section 120 which provides lateral structural integrity while minimizing weight. This lightweight construction allows roofers to move the trolley 100 readily to and among seams S of roof R and, once located on roof R, hoist significant amounts of roofing material thereon. To aid in moving the trolley 100 to the roof and/or among the seams, the bed 105 has a handhold 117 configured to receive a roofer's hand for lifting and moving the trolley 100. Referring also to FIG. 2, the underside of the box section 120 may include one or more ribs 125 to enhance structural integrity. The bed 105 has horizontal flanges 123 for mating with the frames 110.

Each frame 110 includes symmetrically disposed L-shaped brackets 130, each having a horizontal flange 135 and a vertical flange 140. The horizontal flanges 135 mate with and may be welded or otherwise fixed to the horizontal flanges 123 of bed 120. The vertical flanges 140 a and 140 b each have a plurality of throughbores (not shown) that are in registry for receiving a like number of axles 145. A nut 150 retains each axle 145 in each bracket 130.

Referring to FIG. 2, the wheels 115 are rotatingly disposed on each axle 145. Each wheel 115 has a peripheral groove 155 configured to receive and readily roll on roof, guided by seam S, as shown in FIG. 1. Each wheel 115 also may have a peripheral traction element 160, such as a tread, knurling or the like.

Frames 110 a and 110 b are arranged so that the lateral spacing 165 between grooves 155 a and 155 b corresponds to the spacing between seams S, known as seam-to-seam pitch. When constructing standing seam roofs from prefabricated roof panels, this seam-to-seam pitch is fixed or consistent everywhere on the roof, except for unintended minor localized variations. The lateral spacing 165 of wheels 115 allows the trolley 100 to ride along seams S over an entire roof width.

Referring to FIG. 3, in addition to accessing the entire width of a single-level roof R, that is, a section of roof R defining a substantially continuous surface, another embodiment of the invention is a trolley 600 that provides for moving materials to roof sections of different levels to access stepped-up sections of roof R. The trolley 600 is largely identical to trolley 100, except that the trolley 600 includes a deck 603 mounted on frames 610 with threaded fasteners 613 or in any other conventional manner. The deck 603 is constructed from heavy gauge or enhanced-strength material to support, for example, the trolley 100 and materials loaded thereon.

On top of the deck 603 there are two simulated seams 617, which are configured, positioned and aligned similar to the seams in a seamed roof. The height 670 of the deck 603, the vertical spacing 675 between the flange 635 and the axle 645, and the size of the wheel 615, determine the clearance 680 between roof R_(b) and frame 610, are configured to provide an overall trolley height 685, as shown in FIG. 1, corresponding to the step up 190 between stepped adjacent roofing sections R_(a), R_(b). The trolley 600 may include a mechanism for adjusting the height 685.

In practice, when moving materials between stepped sections R_(a), R_(b) of roof R, a second trolley 100 is positioned on a the lower trolley 600. The upper trolley may be pinned or otherwise impermanently fixed to the lower trolley prior to being loaded with materials. Once loaded with materials, roofers may roll the trolley 600 along seam S_(b) with the trolley 100 and materials firmly secured thereon. Upon reaching the step U between section R_(a) and section R_(b), the trolley 100 is disconnected from the trolley 600. The upper trolley 100 then may be rolled onto seam S_(a) along with the materials.

Referring to FIG. 4, another embodiment constructed according to principles of the invention is a trolley 400 that is largely identical to the trolley 100, except that trolley 400 includes a brake 500 which includes two handles 505 interconnected with a rod 510. Referring also to FIG. 5, the rod 510 is fixed to an arm 515 to which is removably attached a brake pad 520. The rod is normally biased to urge the arm and the brake pad against roof R with enough friction to produce sufficient braking force to slow or prevent trolley motion, as shown in FIG. 4. This safety feature significantly reduces job site accidents and injuries.

Referring to FIG. 5, the rod 510 is received through registered throughbores 443 in each vertical flange 440 of frame 410. A shouldered bushing 447 may be employed in the outer flanges 440 a for closer tolerances between the rod 510 and the outer flanges 440 a. The arm 515 has an adjustable collar 453 for frictionally engaging the rod 510. A coil spring 560 has one end (not shown) fixed relative to the rod 510 with an adjustable collar 565 and another end (not shown) fixed relative to the frame 410.

A knuckle 570 is fixed at an orientation on the rod 510 so that when the handle 505 is generally vertical, the knuckle 570 contacts the frame 410 for transferring force exerted against the handle 505 to the frame 410, thence against the trolley 400, and thereby provides motive force to move the trolley as desired. Thus, to move the trolley, a roofer first must rotate either or both handles 505 to distance the brake pad 520 from the roof R, allowing the trolley to move. The roofer then may use the handle(s) 505 to push the trolley along the roof.

FIG. 6 shows another embodiment constructed according to principles of the invention. It includes a trolley 200 that is largely identical to trolley 100, except that trolley 200 includes a brake 300. Preferably, the brake 300 is mounted on one of the frames 210 to which the wheels 215 are mounted. Referring also to FIGS. 7 and 8, the brake 300 includes a handle 305 for rotating a rod 310 to drive a pin 315 and the brake pads 320 mounted thereon against roof R. As with the brake 500, brake 300 is normally biased into a brake position, whereby pin 315 urges brake pads 320 against the roof with enough friction to produce sufficient braking force to slow or prevent trolley motion, as shown in FIG. 6.

The handle 305 is rotatingly mounted on the trolley 200 about a pivot pin 325, while the handle 307 is mounted on a frame 210. The handle 305 drives the rod 310 via a lever 317 extending from rod 310 which is rotatingly connected to the trolley 200 via journals 333, 335 and 340. The rod 310 is drivingly connected to pin 315 via a yoke-and-pin cantilever 330.

The pin 315 is slidingly mounted on the trolley 200 via a spring-loaded cylinder 350, which is comparable to a conventional shock absorber. The pin 315 engages a coil spring (not shown) that abuts an end of the cylinder 350 and normally urges the pin 315 toward the roof. When the pin 315 is drawn away from the roof, spring force increases, either in tension or compression, urging the pin 315 to return to the normally-braked position. The pin 315 has a pad holder 345 welded or otherwise fixed thereto onto which pads 320 are mounted in a conventional manner.

Inasmuch as the invention is subject to many variations and modifications, it is intended that the foregoing description and the drawings shall be interpreted as merely illustrative of the invention defined by the claims below. 

1. A roof trolley system for negotiating a roof step between a lower portion of the roof and an upper portion of the roof, in which both portions of the roof comprises metal panels interconnected by standing seams having uniform spacing, said system comprising a first trolley having wheels adapted to ride on said seams, said wheels being laterally spaced from one another by said uniform spacing, said first trolley also having ridges on its upper surface simulating the roof seams, and a second trolley having wheels adapted to engage said ridges and being laterally spaced from one another by said uniform spacing, and means for securing the second trolley atop said first trolley, whereby when said second trolley is placed on said first trolley, the first trolley may be moved along the seams of the lower portion of the roof until the step is encountered, whereupon the second trolley may be released from the first trolley and rolled onto the seams of the upper portion of the roof.
 2. A system for transporting work materials on a standing seam roof, said system comprising first and second trolleys having wheels with identical lateral spacing, the first trolley having an upper surface with ridges simulating roof seams, whereby a second trolley may be placed with its wheels on said ridges so that, when a step between lower and upper sections of the roof is encountered by the trolley, the second trolley may be rolled off the first trolley onto the upper section of the roof.
 3. The system of claim 2, wherein each of said wheels has a peripheral groove for engaging over a room seam. 